The present invention relates to a post-processing apparatus for performing post-processing on an image-formed sheet, and more particularly, to improvements in a sheet alignment mechanism for aligning and collecting sheets in a post-processing section, and then shifting the position to a post-processing position.
Generally, this kind of post-processing apparatus is known as an apparatus which is connected to a sheet discharge outlet of an image formation apparatus, performs post-processing on an image-formed sheet on a processing tray, and then stores in a stack tray. Then, as the post-processing is known bookbinding processing for collating and collecting sheets to perform binding processing, punching processing for punching a file hole in a sheet, folding processing for folding a sheet and the like.
For example, Patent Document 1 discloses an apparatus which is incorporated into a sheet discharge outlet of an image formation apparatus as a device, stacking image-formed sheets on a processing tray to collect while aligning the position, and shifts the position of a bunch of collected sheets.
The Document proposes a mechanism in which a pair of right and left alignment plates (members) are disposed to be able to shift to positions in the sheet width direction, and concurrently with alignment operation by both of the alignment plates, a bunch of sheets is transported from an alignment position to a processing position. Then, the alignment operation is to correct the posture of a sheet to load by shifting the right and left alignment plates in approach directions and to carry a bunch of sheets.